US4051690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for freezing fish
Assignee: Individual
•
Filing: 1975-07-21
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Granted: 1977-10-04
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Expires: 1995-07-21
Abstract
Abstract A continuous output brine freezing system is disclosed particularly applicable to the freezing of large fish such as tuna on board fishing vessels. The vessels include a series of fish freezing tanks within which the large fish, after being encapsulated in plastic bags and vacuum sealed, are loaded and frozen in sequence. One of said tanks is a brine storage tank and has means of precooling the brine to a temperature of -35° C. Means are provided for feeding the precooled brine from the first tank to the next tank in line and to the remaining tanks in sequence as the tanks are loaded with fish. Means are also provided to remove the brine from the tanks in sequence and to return the brine to the first tank as the fish are frozen. Means are provided to maintain the quality of the brine and to recycle the brine through the system as fish are brought on board and loaded into the tanks, and to unload the frozen fish from the tanks by flotation with brine.
Inventors
- 👤 David John Doust
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:35
CPC Classifications
F; F25; F25D; F25D17/00; F25D17/02; A; A23; A23B; A23B4/00; A23B4/06; A23B4/066; A23B4/068; B; B63; B63B; B63B35/00; B63B35/14; B63B35/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
165 words
Apparatus for continous freezing of large fish on board a fishing vessel comprising a fishing vessel, said fishing vessel including a series of in line insulated fish freezing tanks, the said freezing tanks having hatch openings at deck level, and hermetically sealed hatch covers for said hatch openings, means for encapsulating in plastic bags the individual large fish brought on board the fishing vessel and vacuum sealing the bags, and means to feed the encapsulated fish through the hatch openings of the fish freezing tanks, refrigerating apparatus for feeding brine to the series of fish freezing tanks, the said refrigerating apparatus including feeding and return brine headers, pump means for circulating brine through the said header, individual valve controlled feed pipes between said feed brine header and each freezing tank, and individual valve controlled drains from each freezing tank to said return brine header, and brine collecting tanks in which the brine from the freezing tanks is replenished before being recirculated through the refrigerating apparatus.
Claim 2
Dependent Claim
165 words
Apparatus for continous freezing of large fish on board a fishing vessel comprising a fishing vessel, said fishing vessel including a series of in line insulated fish freezing tanks, the said freezing tanks having hatch openings at deck level, and hermetically sealed hatch covers for said hatch openings, means for encapsulating in plastic bags the individual large fish brought on board the fishing vessel and vacuum sealing the bags, and means to feed the encapsulated fish through the hatch openings of the fish freezing tanks, refrigerating apparatus for feeding brine to the series of fish freezing tanks, the said refrigerating apparatus including feeding and return brine headers, pump means for circulating brine through the said header, individual valve controlled feed pipes between said feed brine header and each freezing tank, and individual valve controlled drains from each freezing tank to said return brine header, and brine collecting tanks in which the brine from the freezing tanks is replenished before being recirculated through the refrigerating apparatus.
Claim 3
Dependent Claim
49 words
Apparatus as set forth in claim 1 in which the said fish freezing tanks are in two rows, one to port and one to starboard, and each row being served by individual refrigerating apparatus and common brine feeding and return headers between said refrigerating apparatus and fish freezing tanks.
Claim 4
Dependent Claim
35 words
Apparatus as set forth in claim 2 in which the brine in the return header is fed to brine collecting tanks and is replenished with water and filtered before being returned to said refrigerating apparatus.
Claim 5
Dependent Claim
40 words
Apparatus as set forth in claim 2 in which each freezing tank is provided with a brine feeding pipe having a perforated portion located at the bottom of the tank, the said perforated portion having at least one relief valve.
Claim 6
Dependent Claim
49 words
Apparatus as set forth in claim 1 in which the said means to recycle the brine includes at least one brine collecting tank, a brine overflow from each freezing tank leading to the brine collecting tank, and means to feed fresh and sea water to said brine collecting tank.
Claim 7
Dependent Claim
39 words
Apparatus as set forth in claim 5 in which the said brine collecting tanks are each provided with a mixing basket into which the brine and fresh and/or salt water are directed before being returned to the refrigeration apparatus.
Claim 8
Dependent Claim
40 words
Apparatus as set forth in claim 1 in which the means to bag the fish and deliver the fish to the freezing tanks include a fish pound and conveyor means between the fish pound and the freezing tank hatch openings.
Claim 9
Dependent Claim
133 words
A continuous method for freezing large fish on board a fishing vessel which comprises precooling calcium chloride brine in the first tank of a series of separate, in-line freezing tanks, passing the precooled brine from said first tank to the second, next in line tank, lowering fish to be frozen into said second tank while progressively lowering the brine level so that the tank can be filled to the top without compressing the fish, hermetically sealing said second tank, circulating the brine from the bottom to the top and controlling the temperature of the brine within the second tank to freeze the fish in the tank, passing brine from said first tank to the third next in-line tank and repeating the sequence until the remaining tanks are fully loaded and the fish frozen.
Claim 10
Dependent Claim
133 words
A continuous method for freezing large fish on board a fishing vessel which comprises precooling calcium chloride brine in the first tank of a series of separate, in-line freezing tanks, passing the precooled brine from said first tank to the second, next in line tank, lowering fish to be frozen into said second tank while progressively lowering the brine level so that the tank can be filled to the top without compressing the fish, hermetically sealing said second tank, circulating the brine from the bottom to the top and controlling the temperature of the brine within the second tank to freeze the fish in the tank, passing brine from said first tank to the third next in-line tank and repeating the sequence until the remaining tanks are fully loaded and the fish frozen.
Claim 11
Dependent Claim
51 words
A continuous method according to claim 8 wherein the specific gravity of the brine in the freezing tanks is maintained at approximately 1.2 as against the specific gravity of the fish (tuna) of 0.98, and the volume of brine in each tank is approximately 80% of the capactiy of the tank.
Claim 12
Dependent Claim
81 words
A continuous method according to claim 8 wherein the frozen fish are unloaded in the following sequence: unsealing said first tank and draining all tanks except said first tank of brine, returning said brine to said first tank to eject the frozen fish therein by flotation, passing the brine from said first tank to said second next in line tank to remove frozen fish therefrom by flotation and repeating the operation until the last tank in line is emptied of fish.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |